Question 297208
Take (1/2) of the x coefficient. 
Place in in the right hand side blank.
Square it and place it in the left hand side blank.
{{{(1/2)(-5/3)=-5/6}}}
{{{-(5/6)^2=25/36}}}
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{{{t^2-(5/3)t +25/36=(t-(5/6))^2}}}